Bug#650035: os-prober: Please enable quiet operation

[Bob Proulx <bob@proulx.com>]

Package: os-prober
Version: 1.49
Severity: wishlist

Since os-prober is run by default when grub is updated upon a kernel
upgrade it causes a lot of noise to appear to the syslog.  Since
scanning the syslog for errors is good practice it means that there is
more information to scan through and to be discarded.  It is more
tedious for me.  Not a showstopper.  But it would be nice if it were
quieter for normal operation when everything is behaving normally.
For example on one host every run generates 24 lines of debug
information.  The debug information is useful to someone developing
and debugging the scripts but on a stable production host isn't
changing.

It would be very nice if the debug information were optional.  It
would be very nice to be able to set a quiet variable in order to turn
off the debug information.  I am fine with keeping verbose the default
behavior.  As a suggestion, perhaps something like this following
(untested) code snippet in /usr/share/os-prober/common.sh file.

VERBOSE=true
if [ -r /etc/default/os-prober ]; then
  . /etc/default/os-prober  # Available to set VERBOSE=false
fi

debug() {
  if $VERBOSE; then
    log "debug: $@"
  fi
}

That would preserve the existing behavior yet enable people like
myself to optionally quiet it down on stable production hosts.

Thank you for maintaining Debian!

Bob